Laminating film and methods of use thereof

ABSTRACT

A laminating film and methods of use with xerographic prints. The laminating film comprises an adhesion promoter comprising a hydrolytic silane compound that imparts improved adhesion and which can be used in laminating applications conducted at high and as well as low temperature ranges.

BACKGROUND

The present disclosure generally relates to a laminating film andmethods of use with xerographic prints. The laminating film comprises anadhesion promoter comprising a hydrolytic silane compound that impartsimproved adhesion and which can be used in laminating applicationsconducted at high as well as low temperature ranges.

In imaging devices, a light image of an original to be copied isrecorded in the form of a latent image upon a photosensitive member, andthe latent image is subsequently rendered visible by the application ofresin particles and pigment particles, or toner. The visible toner imageis then in a loose powdered form and can be easily disturbed ordestroyed. The toner image may be fixed or fused upon a support, whichmay be a support sheet such as plain paper, using a fuser roll.

To ensure and maintain good release properties of the fuser roll, it hasbecome customary to apply release agents to the fuser roll during thefusing operation. These materials are applied as thin films of, forexample, nonfunctional silicone oils or mercapto- or amino-functionalsilicone oils, to prevent toner offset.

U.S. Pat. No. 4,029,827 discloses the use of polyorganosiloxanes havingmercapto functionality as release agents. U.S. Pat. No. 4,101,686 andU.S. Pat. No. 4,185,140 disclose polymeric release agents havingfunctional groups such as carboxy, hydroxy, epoxy, amino, isocyanate,thioether, or mercapto groups. U.S. Pat. No. 5,157,445 discloses tonerrelease oil having a functional organopolysiloxane.

Fuser oil unavoidably contaminates the surface of prints duringxerographic printing process. Because the fuser oil is chemically boundon the paper surface during the hot fusing process, especially forexample with mercapto or amino functionalized fuser oil, it may bedifficult to wipe off the fuser oil, and the surface free energy (SFE)of the xerographic prints is significantly lowered because of the oilcontamination and thus causes poor binding between the adhesive andprints.

Xerographic prints sometimes need to be laminated with PET, PP, PE orPVC films. One additional layer of polymeric materials such asthermoplastic EVA copolymer resin is extrusion coated onto these films.U.S. Pat. No. 7,368,165 discloses the process for the production ofcoated polymeric film. U.S. Pat. No. 7,323,239 discloses protectivefilms coated with EVA copolymer. U.S. Pat. No. 6,645,336 discloses theextrusion coating process for making these thermal plastic polymericmaterials coated films. U.S. Pat. No. 4,234,644 discloses the compositelamination film for electrophoretically toned images

SUMMARY

According to embodiments illustrated herein, there is provided animproved laminating film and methods of use with xerographic prints.

In one embodiment, there is disclosed a laminating film for laminatingxerographic prints, comprising a plastic substrate, and an adhesivecoating disposed on a surface of the plastic substrate, wherein theadhesive coating comprises an adhesion promoter comprising a silanecoupling component selected from the group consisting of a hydrolyticsilane compound, a hydrolytic product of a hydrolytic silane compound,and mixtures thereof.

In another embodiment, there is provided a bonded article, comprising axerographic print, an adhesive coating disposed on the xerographicprint, a laminating film disposed on the adhesive coating, thelaminating film comprising a plastic substrate, and an adhesion promoterpresent at either an interface between the xerographic print and theadhesive coating or within the entire adhesive coating, wherein theadhesion promoter comprises a silane coupling component selected fromthe group consisting of a hydrolytic silane compound, a hydrolyticproduct of a hydrolytic silane compound, and mixtures thereof.

In yet another embodiment, there is provided a method for laminatingxerographic prints, comprising providing a xerographic print, applyingan adhesive coating on the xerographic print, applying a laminating filmover the xerographic print, wherein the laminating film comprises aplastic substrate, and an adhesive coating disposed on a surface of theplastic substrate, wherein the adhesive coating comprises an adhesionpromoter comprising a hydrolytic silane compound and further wherein thelaminating film is applied in a manner such that the xerographic printcontacts the adhesive coating on a side opposite that which is disposedon the surface of the plastic substrate, and subjecting the xerographicprint and laminating film to heat.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding, reference may be had to the accompanyingfigure.

FIG. 1A represents a simplified side view of a laminating film inaccordance with a first embodiment of the present embodiments;

FIG. 1B represents a simplified side view of a laminating film inaccordance with a second embodiment of the present embodiments; and

FIG. 2 represents a bonded article formed from the laminating methods inaccordance with the present embodiments.

Unless otherwise noted, the same reference numeral in different Figuresrefers to the same or similar feature.

DETAILED DESCRIPTION

As explained above, it is known to apply release agents to the fuserroll to provide the necessary release of a substrate containing an imagethereon from the fuser roll after the toner image has been formed on thesubstrate. Thus, xerographic prints may be contaminated by a releaseagent such as silicone fuser oil due to the printing process. Somerelease agent may remain on a toner image that may cover any portion ofthe substrate and on the substrate itself. In other words, some releaseagent may remain on a final substrate having an image thereon and may atleast partially cover a substrate having no toner image or a substratehaving a toner image thereon. “Partially” refers to the release agentcovering from above 0 percent to less than 100 percent of the substrate,such as from about 10 percent to about 90 percent or from about 20percent to about 80 percent of the substrate. The release agent maychemically bond to the surface of the prints because of the reactivefunctional group such as amino- or mercapto-functional group in fuseroil during fusing process at high pressure and high temperature. Thesurface free energy (SFE) of the prints may thus dramatically drop froma range of higher than about 30 mN/m for substrates such as paper to arange of from about 8 mN/m to less than about 30 mN/m. Generally,commercially available hot melt adhesives bind to substrates having aSFE higher than about 30 mN/m.

Any release agent remaining on the substrate, with or without a tonerimage thereon, may be detrimental to an adhesive attempting to adhere tothe substrate having a toner image. This is particularly important whenthe substrate is to be laminated or coated with a hot melt adhesive,such as an adhesive used in bookbinding. This release agent may alsoprevent materials utilizing adhesives, for example, POST-IT® notes, fromadhering to the substrate.

Release agents used in releasing a substrate from a fuser roll in animaging device include poly-organofunctional siloxanes, such asamino-functional silicone oils, such as methyl aminopropyl methylsiloxane, ethyl aminopropyl methyl siloxane, benzyl aminopropyl methylsiloxane, dodecyl aminopropyl methyl siloxane, aminopropyl methylsiloxane, and the like.

Disclosed in U.S. application Ser. No. 11/743,447, and US PublicationNos. 2008/0171826 and 2008/0071043, are adhesion promoters that promotethe adhesion of an adhesive to a substrate with low surface free energy.However, those adhesion promoters are directed to applications involvingadhesives used directly on traditional paper substrates, for example, inbookbinding applications.

Synthetic media made of specially treated plastic films are beingincreasingly used for printing applications where moisture and/orcontamination would damage traditional paper substrates. Such plasticsubstrates are durable and tear resistant, and are finding increasinguse in labels, tags, maps, menus, posters, manuals, books, covers, andvarious cards such as identification cards, gift cards, credit cards,hotel key cards, and the like. The use of such material technology israpidly growing and replacing traditional paper substrates.

As discussed above, poor adhesion issues are often encountered forxerographic prints on traditional paper substrates due to fuser oilcontamination. In cases involving plastic substrates, such as giftcards, credit cards or hotel key cards, there is an added complicationin that xerographic prints printed on the synthetic papers have to belaminated together with films such as polyester, including polyethyleneterephthalate (PET) film which may be pre-coated with ethylene vinylacetate (EVA) adhesive. Poor adhesion is also encountered when the filmsare laminated together with the xerographic prints printed on syntheticpaper because of the residual fuser oil contamination. Thus, there is aneed for adhesion promoters and methods of use that can facilitateadequate adhesion for plastic substrates, and also be used in laminatingmethods at various temperature ranges.

Disclosed herein is the incorporation of the silane promoters into alaminating film as well as an improved laminating method for plasticsubstrates with xerographic printed synthetic media. The embodimentsdisclosed herein have demonstrated dramatically improved adhesion forthe laminating application. The use of the specific adhesion promoters,comprising a hydrolytic silane compound, promotes and dramaticallyimproves adhesion between the synthetic media and the laminatingmaterial. The silane adhesion promoters can be implemented by differentmanners, including use as a primer either on pre-coated adhesive filmsor on xerographic printed synthetic media, or incorporated into anadhesive coating. Specific types of silane promoter are also disclosedfor laminating methods at high temperature.

As used herein, and without any indication to the contrary, “syntheticmedia” or “substrate” refers to plastic substrates, such as withoutlimitation, polyethylene, polypropylene, poly(vinyl chloride) (PVC),Polyester (PET) and mixtures thereof.

The substrate may be at least partially covered by a release agent. Theadhesion promoter may also promote adhesion of an adhesive to asubstrate having no toner image or a substrate having a toner imagewithout being covered by a release agent.

It is desirable to have an adhesive with a stable viscosity that ismaintained constant during the application process. For example, theadhesive desirably has a stable viscosity at the applicationtemperature, such as a temperature from about 100° C. to 200° C., suchas from about 140° C. to about 190° C. or from about 150° C. to about180° C.

An adhesive that incorporates a conventional adhesion promoter mayencounter pot life issue. That is, the viscosity of the adhesive may notbe able to be kept constant long enough in a hot pot to meet therequirements during the extrusion coating process for the laminatingfilm preparation process. The viscosity of the adhesive containing aconventional adhesion promoter may continuously increase and causeoperating problems. This can be especially problematic at high extrusioncoating temperature during the laminating film preparation process.

It is thus desirable to have an adhesion promoter that can be added tothermalplastic resin such as EVA copolymer, or hot melt adhesive orpressure sensitive adhesive and at the same time maintain the thermalstability of the adhesive, or maintain a long enough pot life andconstant viscosity of the adhesive during the application process.

A thermally stable adhesive is one that substantially maintains itsviscosity and adhesion properties over a period of time. A stableviscosity, for example, is an increase or decrease in viscosity within1000 cp over the aging process at the application temperature, such asfrom about 100 to about 800 cp over 8 hours at an applicationtemperature or from about 200 to about 600 cp over 8 hours at anapplication temperature.

In embodiments, the adhesion promoter before treatment may be a silanecompound, for example, a silane compound such as an alkyloxysilanecompound or a glycidoxy silane compound. Further examples includeorganic silane compounds, which may be represented by the followingformula:

—Si(R)3-mXm

wherein R is a C₁-C₃₀ hydrocarbyl including an alkyl, an aryl, a vinyland the like, wherein said hydrocarbyl may further contain a halogen,nitrogen, oxygen or sulfur atom. Illustrative examples of R may includemethyl, ethyl, propyl, octyl, phenyl, methacryloxypropyl, aminopropyl,aminoethylaminopropyl, phenylaminopropyl, chloropropyl, mercaptopropyl,acryloxypropyl, 3-glycidoxypropyl, trifluoropropyl,heptadecafluorodecyl, and isocyanatopropyl group and the like. X mayrepresent a hydrolyzable functional group, a C₁-C₂₀ alkoxy group, ahalogen or a hydrogen atom, and m is an integer of 1, 2 or 3.

In embodiments, R may be a non-hydrolyzable organic group, X may be ahydrolytic group and m may be an integer of 1, 2 or 3. X may include ahalide, a hydroxyl group, a carboxylate group, an alkoxy group, anarylalkyloxy group and an aryloxy group. The hydrolytic silane compoundmay contain in total two of the hydrolytic X group

In embodiments, the hydrolytic silane compound may include a functionalgroup. Examples of functional groups may include, for example but notlimited to, an amino group, a mercapto group, an epoxy group and a vinylgroup.

Examples of silane compounds suitable for use herein includeaminoalkylsilane, mercaptoalkylsilane and mixtures thereof, for example,4-aminobutyltriethoxysilane, 1-amino-2-(dimethylethoxysilyl)propane,N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane,N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane,(aminoethylaminomethyl)phenethyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-aminoethyl)-3-aminopropylsilanetriol,N-(2-aminoethyl)-3-aminopropyltriethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,N-aminoethyl-AZA-2,2,4-trimethylsilacyclopentane,N-(6-aminohexyl)aminomethyl-trimethoxysilane,N-(6-aminohexyl)aminopropyl-trimethoxysilane,N-(2-aminoethyl)-11-aminoundecyl-trimethoxysilane,3-aminopropylmethylbis(trimethylsiloxy)silane,3-aminopropyldimethylethoxysilane, 3-aminopropyltrimethoxysilane,3-aminopropyltris(methoxyethoxyethoxy)silane,3-(triethoxysilyl)propylsuccinic anhydride,tris(3-trimethoxysilylpropyl)iso-cyanurate,(3-trimethoxysilylpropyl)diethylene-triamine, methyltrichlorosilane,dimethyldichlorosilane, methyltriethoxysilane, ethyltrichlorosilane,ethyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, propyltrimethoxysilane, amino silanehydrochloride, 3-glycidoxypropyl trimethoxysilane (Z-6040, availablefrom Dow Coming; KBM 403, available from Shin-Etsu),methyltrimethoxysilane (Z-6070, available from Dow Coming; KBM 13,available from Shin-Etsu), methacryloxypropyltrimethoxysilane (Z-6030,available from Dow Coming; KBM502, available from Shin-Etsu),aminopropyltrimethoxysilane (Z-6011, available from Dow Coming; KBM903,available from Shin-Etsu), aminoethylaminopropyltrimethoxysilane(KBM603, available from Shin-Etsu or DOW Z 6032, available from DowComing; KBM603, available from Shin-Etsu),trifluoropropyltrimethoxysilane (KBM7103, available from Shin-Etsu),heptadecafluorodecyltrimethoxysilane (KBM7803, available fromShin-Etsu), isocyanatopropyltriethoxysilane (KBE9007, available fromShin-Etsu), aminopropyltriethoxysilane (KBE903, available fromShin-Etsu), aminoethylaminopropyltriethoxysilane (KBE603, available fromShin-Etsu), alkyltrimethoxysilane (DOW HV 10, available from DowKorning), and a coating having trifluoropropy trimethoxysilane,vinylmethoxysilane, tetra(2-methoxyethoxy)silane (DOW 4040 Prime Coat,available from Dow Corning), mixtures thereof, and the like.

The adhesion promoter disclosed herein may include more than one silanecompound, for example, the adhesion promoter may include from 1 to about5 silane compounds, such as from 1 to 3 silanes

In embodiments, the silane compound is admixed with aqueous buffersolution before incorporation into an adhesive. The aqueous buffersolution may include a buffer agent. The aqueous buffer solution is madeby dissolving the buffer agent into distilled water. The buffer agentmay be an inorganic salt, for example an alkali metal phosphate, analkali metal sulfite and the like or an aqueous solution of an inorganicsalt. Other suitable buffer agents include aqueous solutions ofpotassium phosphate monobasic, potassium phosphate dibasic, sodiumhydrogen sulfite, mixtures thereof and the like, for example dissolvedin distilled water.

In embodiments, the aqueous buffer solution may be prepared to form fromabout 1% to about 50% by weight buffer solution, such as, from about 5%to about 25% by weight buffer solution, and for example from about 5% toabout 15% by weight buffer solution.

In embodiments, the pH of the buffer solution may be, for example, fromabout 2 to about 10, such as from about 4 to about 9.

In embodiments, the aqueous buffer solution may be added to the silanecompound, for example in a silane to buffer solution ratio from 1:0.005to 1:0.5, such as a ratio of 1:0.15 and for example a ratio of 1:0.35.The buffer solution may be added to the silane compound while agitatingthe silane compound at room temperature. The silane compound temperaturegoes up after the adding of the buffer solution because this may be anexothermic reaction process. The adhesion promoter may be kept agitatingfrom about 1 hour to about 3 hours before it is incorporated into hotmelt adhesives or pressure sensitive adhesives. The shelf life for theadmixed silane may be as long as three days or longer at roomtemperature.

The admixed silane adhesion promoter described herein provides at leasttwo beneficial functions in order to promote adhesion of the adhesive tothe substrate: (1) a reactive silicone group, that is, a group reactivewith silicone, for bonding with the Xerographic print or substrate, suchas a methoxy or an ethoxy group, and (2) an organic component forcompatibility with the adhesive.

The admixed silane adhesion promoter described herein may provide atleast two beneficial functions in order to promote adhesion of theadhesive to the substrate: (1) a reactive silicone group, that is, agroup reactive with silicone, for bonding with the xerographic print orsubstrate, such as a methoxy or an ethoxy group, and (2) an organiccomponent for compatibility with the adhesive.

The admixed adhesion promoter may be utilized in a variety of ways topromote the adhesion of an adhesive to a substrate. In embodiments, theadmixed adhesion promoter may be used as a separate coating on thesubstrate or an adhesive coating to be used as a primer, dispersedwithin a release agent, or incorporated into an adhesive. In FIG. 1A,there is depicted a laminating film 30 for laminating xerographic printswhich comprises a plastic substrate 5, and an adhesive coating 10disposed on a surface of the substrate 5. The adhesive coating 10further comprises an adhesion promoter comprising a hydrolytic silanecompound 20. The plastic substrate 5 may be selected from the groupconsisting of polyethylene, polypropylene, poly(vinyl chloride) andmixtures thereof. In FIG. 1A, the adhesion promoter is incorporatedalong a surface of the adhesive coating 10 as a primer layer 15. Inanother embodiment, depicted in FIG. 1B, the adhesion promoter 20 isincorporated into the adhesive coating 10. The adhesive coating may havea thickness of from about 10 microns to about 200 microns. The plasticsubstrate may have a thickness of from about 50 microns to about 500microns. The xerographic prints may be from about 100 microns to about500 microns.

In FIG. 2, there is depicted a bonded article 35 formed by thelaminating methods described herein. The bonded article 35 comprises axerographic print 25, and a laminating film 30 for laminatingxerographic prints. The laminating film 30 comprises a plastic substrate5 and an adhesive coating 10 disposed on a surface of the substrate 5,which further comprises an adhesion promoter comprising a hydrolyticsilane compound 20. The hydrolytic silane compound can be selected, forexample, from the group consisting of an aminoalkylsilane, amercaptoalkylsilane or mixtures thereof.

In the present embodiments, there is provided laminating methods forxerographic prints which can be used in both low temperatureapplications (e.g., <100° C.) and high temperature applications(e.g., >=100° C.). The method comprises providing a xerographic print tobe laminated, and applying a laminating film over the xerographic print.The laminating film comprises a plastic substrate, and an adhesivecoating disposed on a surface of the substrate so that the adhesivecoating will bind the plastic substrate to the xerographic print. Theadhesive coating further comprises an adhesion promoter comprising ahydrolytic silane compound.

As discussed above, poor adhesion issues are often encountered for thexerographic prints printed on the traditional paper due to aminofunctional fuser oil contamination. Because the fuser oil is chemicallybound on the paper surface during hot fusing process, the surface freeenergy of the prints is significantly lowered and this causes the pooradhesion problem. The same problems are encountered for synthetic mediaas demonstrated in Tables 1 and 2. Table 1 demonstrates how the surfacefree energy is lowered after the synthetic media is run through a XEROX®IGEN3® printer with amino fuser oil (available from Wacker ChemicalCorporation, Adrian, Mich.) with and without toner on the surface.Artisyn, Teslin and Dura paper are all synthetic papers which arecommercial available on market. All grades of Teslin® synthetic printingsheet are continuous, homogeneous materials composed of polyethylene andinert fillers formed into a sheet with a microporous void structure.Xerox Digital Color DuraPaper is a heavyweight synthetic media andspecially coated with 4 mil polyester to resist tearing, smudging anddeterioration

TABLE 1 SFE (mN/m) at 10 seconds Substrate Description 12 pt Artisyn 14pt Teslin 14 pt Dura Original - No Oil 45.32 45.08 41.63 No Toner -Fuser 19.18 34.48 31.00 Fluid I Solid Black Toner - 23.23 23.66 22.69Fuser Fluid ITable 2 demonstrates the reduction in surface free energy of poly(vinylchloride) films after being run through a XEROX® IGEN3® printer withamino fuser oil with and without toner on the surface.

TABLE 2 SFE (mN/m) at 10 seconds Substrate Description 10 mil PVC 13 milPVC 26 mil PVC Original - No Oil 42.24 42.82 44.80 No Toner - Fuser31.13 30.60 32.18 Fluid I Solid Black - Fuser 27.35 29.22 29.28 Fluid I

The present embodiments disclose three approaches to improve theadhesion on xerographic prints printed on synthetic media laminated withfilms such as polyester, polyethylene and polypropylene films which arepre-coated with adhesives such as EVA-based copolymers. One approach isto use amino- or mercapto-functional silane as a primer to apply eitheron the laminating films or on xerographic synthetic prints to improvethe laminating adhesion. The second approach is to incorporate amino- ormercapto-functional silane with adhesives, such as for example, EVA-baseadhesives, before the adhesive is coated on a film, for example,polyester films. This second approach is useful for low temperaturelaminating methods. The third approach is to incorporate pre-treatedamino- or mercapto-functional silane with adhesives, such as forexample, EVA-base adhesives, before the adhesive is coated on a film,for example, polyester films. The silane compound may be pre-treated byusing buffer solutions such as a potassium phosphate monobasic aqueoussolution. This third approach is useful for high temperature laminatingmethods.

Suitable hot melt adhesives for use herein include most commerciallyavailable hot melt adhesive, such as polyethylene, poly(ethylene/vinylacetate), polystyrene, polyamide, a polyolefin based polymer, polyester,phenol-formaldehyde resin, etc., of a homopolymer or a block copolymerbased hot melt adhesives and thermal plastic resins such as EVAcopolymers

When the admixed silane compound used as an adhesion promoter is addedto a commercially available hot melt adhesive or the thermal plasticresin, for example EVA copolymers, the first step is to heat theadhesive or the thermal plastic resin to the application temperatureuntil the adhesive or the thermal plastic resin is substantially meltedor flows. Then the adhesion promoter is slowly added to the adhesivewhile keeping the application temperature and the speed of the agitationcontrolled. The application temperature is determined by the viscosityof the adhesive.

The adhesion promoter may be added to the adhesive formulation inamounts of from about 0.05 weight percent to about 5 weight percent ofthe base adhesive, such as from about 0.5 weight percent to about 3weight percent or from about 1 weight percent to about 2 weight percentof the adhesive formulation.

By chemically bonding to both the adhesive and the substrate, thepretreated adhesion promoter promotes the adhesion of an adhesive to asubstrate having an oil contaminated surface with a Surface Free Energy(SFE) from less than about 30 mN/m, such as from about 8 mN/m to lessthan about 30 mN/m, such as from about 10 mN/m to about 28 mN/m or fromabout 15 mN/m to about 25 mN/m.

In embodiments, the adhesive may display a viscosity ranging for examplefrom about 1,000 centipose to about 20,000 centipose at temperaturesranging for example from about 120° C. to about 200° C.

Suitable hot melt adhesives for use herein may include thermoplastics ormaterials which appear to be thermoplastic including components such aspolymer resins, tackifiers, waxes, plasticizers, antioxidants and filleror combinations thereof.

The most commonly used hot melt adhesive is based on ethylene vinylacetate (EVA) resins. Other polymers commonly used in hot melt adhesivesand pressure sensitive adhesives include low density polyethylene,poly(ethylene/vinyl acetate), polyvinyl alcohol, polystyrene,polyamides, polyalkylene oxide, polyacrylate, ethylene acryliccopolymers, polypropylene(atactic), phenoxy resins, polyesters, APAO,polyesteramides, polyparaffins, polyurethanes, polyurethane prepolymers,thermalplastic acrylic polymers butyl rubbers, polyvinyl acetate andcopolymers, styrenic block copolymers (SIS, SBS, SEBS),phenol-formaldehyde resin of polymer or block copolymer, natural rubber,and a copolymer thereof etc.

Examples of suitable polymer resins that may be optionally used forlaminating films can be pure copolymer. For example EVA polymer havingdifferent melt index with different VA grades such as 18% and 28% VAgrades.

Other polymers that can be used in laminating films include poly(methylmethacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propylmethacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methylacrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propylacrylate-butadiene), poly(butyl acrylate-butadiene), poly(methylmethacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propylmethacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methylacrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propylacrylate-isoprene) and poly(butyl acrylate-isoprene),poly(styrene-butadiene), poly(methylstyrene-butadiene),poly(styrene-isoprene), poly(methylstyrene-isoprene),poly(styrene-propyl acrylate), poly(styrene-butyl acrylate),poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylicacid), poly(styrene-butadiene-acrylonitrile-acrylic acid),poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butylacrylate-methacrylic acid), poly(styrene-butylacrylate-acrylononitrile), and poly(styrene-butylacrylate-acrylononitrile-acrylic acid), block copolymer such asstyrene-isoprene-styrene (SIS) or styrene-butadiene-styrene (SBS),polyester or mixtures thereof and the like. In embodiments, the polymerresin content in the hot melt adhesives or pressure sensitive adhesivesmay be in the amount of from about 20 to about 100% by weight, such asfrom about 25 to about 90% by weight.

Examples of optional tackifiers used in hot melt adhesives and pressurehydrocarbons or mixed C5/C9 resins, modified rosin, natural tackifiersare rosin acid derivatives and their esters, terpene resins, puremonomers, hydrogenated pure monomers etc. and combinations thereofExamples of the optional tackifier suitable for use herein may beEastotac H100-W, Regalite S1100, Foralyn 110 from Eastman Chemical. Inembodiments, the optional tackifier may be added to the adhesive, forexample, in the amount of from about 5 to about 30% by weight.

Examples of the optional wax suitable for use herein may include naturaland synthetic waxes. Examples of natural waxes may include animal waxsuch as beeswax and lanolin wax, vegetable wax such as carnauba wax,mineral wax such as montan wax and paraffin wax, microcrystalline waxand slack wax. Examples of synthetic waxes suitable for used herein mayinclude polyethylene wax such as homopolymer wax and copolymer wax andmodified polymer wax, polypropylene wax such as homopolymer wax andmodified polymer wax, semicrystalline flexible polyolefines, andFisher-Tropsch wax such as homopolymer wax and modified polymer wax. Inembodiments, the optional wax may be added to the adhesive, for example,in the amount of from about 5 to about 20% by weight. In embodiments,the wax may have a melting point for example from about 50° C. to about150° C.

Examples of the optional antioxidant suitable for use herein includeprimary and secondary antioxidant or multifunctional antioxidant,hydroxylamines, N,N′-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide) (IRGANOX 1098, available from Ciba-Geigy Corporation),2,2-bis(4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy))ethoxyphenyl)propane(TOPANOL-205, available from ICI America Corporation),tris(4-tert-butyl-3-hydroxy-2,6-dimethyl benzyl)isocyanurate (CYANOX1790, 41,322-4, LTDP, Aldrich D12,840-6), 2,2′-ethylidenebis(4,6-di-tert-butylphenyl)fluoro phosphonite (ETHANOX-398, availablefrom Ethyl Corporation), tetrakis(2,4-di-tert-butylphenyl)-4,4′-biphenyldiphosphonite (ALDRICH 46,852-5; hardness value 90), pentaerythritoltetrastearate (TCI America #PO739), tributylammonium hypophosphite(Aldrich 42,009-3), 2,6-di-tert-butyl-4-methoxyphenol (Aldrich25,106-2), 2,4-di-tert-butyl-6-(4-methoxybenzyl)phenol (Aldrich23,008-1), 4-bromo-2,6-dimethylphenol (Aldrich 34,951-8),4-bromo-3,5-didimethylphenol (Aldrich B6,420-2), 4-bromo-2-nitrophenol(Aldrich 30,987-7), 4-(diethyl aminomethyl)-2,5-dimethylphenol (Aldrich14,668-4), 3-dimethylaminophenol (Aldrich D14,400-2),2-amino-4-tert-amylphenol (Aldrich 41,258-9),2,6-bis(hydroxymethyl)-p-cresol (Aldrich 22,752-8),2,2′-methylenediphenol (Aldrich B4,680-8),5-(diethylamino)-2-nitrosophenol (Aldrich 26,951-4),2,6-dichloro-4-fluorophenol (Aldrich 28,435-1), 2,6-dibromo fluorophenol (Aldrich 26,003-7), α-trifluoro-o-cresol (Aldrich 21,979-7),2-bromo-4-fluorophenol (Aldrich 30,246-5), 4-fluorophenol (AldrichF1,320-7), 4-chlorophenyl-2-chloro-1,1,2-tri-fluoroethyl sulfone(Aldrich 13,823-1), 3,4-difluoro phenylacetic acid (Aldrich 29,043-2),3-fluorophenylacetic acid (Aldrich 24,804-5), 3,5-difluoro phenylaceticacid (Aldrich 29,044-0), 2-fluorophenylacetic acid (Aldrich 20,894-9),2,5-bis(trifluoromethyl)benzoic acid (Aldrich 32,527-9),ethyl-2-(4-(4-(trifluoromethyl)phenoxy)phenoxy)propionate (Aldrich25,074-0), tetrakis(2,4-di-tert-butyl phenyl)-4,4′-biphenyldiphosphonite (Aldrich 46,852-5), 4-tert-amyl phenol (Aldrich 15,384-2),3-(2H-benzotriazol-2-yl)-4-hydroxy phenethylalcohol (Aldrich 43,071-4),NAUGARD 76, NAUGARD 445, NAUGARD 512, AND NAUGARD 524 (manufactured byUniroyal Chemical Company), and the like, as well as mixtures thereof.

In embodiments, the optional antioxidant may be added to the adhesive,for example, in the amount of from about 0.1% to about 2%.

Examples of the optional filler suitable for use herein include titaniumdioxide, calcium carbonates, zinc oxide, clays, talcs and bariumsulfate.

In embodiments, the optional filler may be added to the adhesive, forexample, in the amount of from about 0.1% to about 5%.

In embodiments, the adhesive may be coated on a plastic substrate, andthe adhesion promoter may be present at the interface between theadhesive and the Xerographic prints.

Various exemplary embodiments encompassed herein include a method ofimaging which includes generating an electrostatic latent image on animaging member, developing a latent image, and transferring thedeveloped electrostatic image to a suitable substrate.

While the description above refers to particular embodiments, it will beunderstood that many modifications may be made without departing fromthe spirit thereof The accompanying claims are intended to cover suchmodifications as would fall within the true scope and spirit ofembodiments herein.

The presently disclosed embodiments are, therefore, to be considered inall respects as illustrative and not restrictive, the scope ofembodiments being indicated by the appended claims rather than theforegoing description. All changes that come within the meaning of andrange of equivalency of the claims are intended to be embraced therein.

EXAMPLES

The example set forth herein below and is illustrative of differentcompositions and conditions that can be used in practicing the presentembodiments. All proportions are by weight unless otherwise indicated.It will be apparent, however, that the embodiments can be practiced withmany types of compositions and can have many different uses inaccordance with the disclosure above and as pointed out hereinafter.

Suitable silane promoters for laminating application between plasticsubstrate and xerographic printed synthetic media may comprise ahydrolytic silane compound such asN-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and their derivativesfrom pre-treatment with buffer solutions.

Example 1

Xerographic prints printed on synthetic media were generated by using aXEROX® IGEN3® machine. Synthetic papers made of specially treatedplastic films are commonly used for printing applications where moistureand/or contamination would damage traditional paper. They are durableand tear resistant, and are finding increasing use in labels, tags,maps, menus, posters, manuals, books, covers, ID and cards such as giftcard, credit card and hotel key card etc. This is a rapidly growingniche market in terms of materials (polyethylene, polypropylene, PVC),technology (mono-layer, co-extruded, multi-layer), applications andpotential traditional paper replacement. Most synthetic media ismanufactured using oil-based synthetic resins (plastics). As a result,synthetic paper possesses characteristics resembling those of plasticfilm, but looks almost indistinguishable from regular paper. Syntheticpaper outperforms regular paper in terms of moisture resistance (almostno structural deterioration or deformation when wet) and durability(resistance to tearing). In addition, it is extremely resistant tochemicals and oils and has an exceptionally smooth surface finish. Aminofunctional silane was applied on a polyester film which was coated withEVA copolymer. The thickness of the synthetic media can be from 100microns to around 700 microns and the adhesive coating thickness can befrom 1 microns to 200 microns. Two synthetic mediums were laminated withthe polyester film. T-peel tests were conducted on these laminatedsamples by using an INSTRON® tester (available from Instron, Norwood,Mass.) to measure the peel force necessary to separate the twoadherents.

Silane adhesion promoter can be applied on the top of the adhesive layerto be used as a primer or incorporated into the adhesives such as EVAcopolymer.

For adhesive coating process at high temperature, the silane adhesionpromoter may need to be pre-treated in order to get good thermalstability of the adhesive. The silane solution was prepared as follows:5% silane solution was prepared by adding 2.5 gN-(2-aminoethyl)-3-aminopropyltrimethoxysilane (A-2120) into 45 gMethanol and then adding 2.5 g distilled water. Five laminatingconditions were tested on two synthetic mediums: (1) Original paper (Nooil, not run through XEROX® IGEN3® machine) laminated with originalpolyester film; (2) Oiled but no toner paper (the synthetic media wasrun through XEROX® IGEN3® machine by using Fuser fluid I fuser oilwithout toner) laminated with original polyester film; (3) Oiled withtoner paper (the synthetic media was run through XEROX® IGEN3® machineby using Fuser fluid II fuser oil with solid black toner) laminated withoriginal polyester; (4) Oiled but no toner paper (the synthetic mediawas run through XEROX® IGEN3® machine by using Fuser fluid I fuser oilwithout toner) laminated with polyester film coated with adhesionpromoter solution by a Meyer Rod coating machine, specifically Meyer Rod#4, (5) Oiled with toner paper (the synthetic media was run throughXEROX® IGEN3® machine by using Fuser fluid I fuser oil with solid blacktoner) laminated with polyester film coated with adhesion promotersolution by Meyer Rod #4.

Laminating samples were prepared as follows: Synthetic media waslaminated with 2.65 mil polyester with 7 mil EVA Copolymer with meltindex 15 and vinyl acetate (VA) content 16%. KAPTON® tape (hightemperature 3M SCOTCH® 5490 with 1 inch width) was used on top of theedge of the polyester film to create one-inch gripping lead edge. A GBCPouch Laminator (GBC3500 PRO™ SERIES) (available from ACCO Brands Corp.,Lincolnshire, Ill.) was used for laminating at a laminating temperatureof 150° C. (highest) and a laminating speed of 8 inches/minute (lowest)(Dial Setup 1). The specimen dimension was 15 mm×200 mm.

The T-Peel Test procedure used in the examples followed the ASTMD1876-01 Standard Test Method for Peel Resistance of Adhesives: theINSTRON® load cell was 50N, peel speed was 254 mm/min, and peel lengthwas 300 mm. Five replicates were performed for each measurement and theresults of the T-peel force on the synthetic media laminated withpolyester film are shown in Table 3.

TABLE 3 Synthetic Media Condition 14 pt Dura 12 pt Artisyn No Oil 12.6648.08 Oil 7.14 37.67 Oil + Solid black toner 4.93 0.78 Oil + A-212023.24 50 Oil + Solid black toner + A- 12.03 9.3 2120

Example 2

Three plastic poly(vinyl chloride) films were printed on XEROX® IGEN3®and then were laminated with polyester film coated with EVA copolymer.T-peel test were conducted on these laminating samples by using anINSTRON® tester. Sample preparation and test procedure are the same asprovided in Example 1. The results of the T-peel force on the poly(vinylchloride) substrate laminated with polyester film are shown in Table 4.

TABLE 4 PVC Oil + A- Oil + Toner + Condition No Oil Oil 2120 Oil + TonerA-2120 10 mil PVC 45 7.27 45 0.39 12.18 13 mil PVC 45 8.77 45 0.44 13.4726 mil PVC 45 3.87 45 0.24 13.98

Based on the above, it is demonstrated that the bonding betweensynthetic media and laminating films coated with EVA copolymer can beimproved dramatically by using amino functional silane as a primereither on laminating films or on synthetic xerographic prints.

In addition, it is demonstrated that the bonding between synthetic mediaand laminating films coated with EVA copolymer can be improveddramatically if the amino functional silane is incorporated into theadhesives such as EVA copolymer before the copolymer is coated on thefilm (e.g., polyester, polyethylene or polypropylene films). Becauseamino functional silane can dramatically improve the adhesion onEVA-based hot melt adhesives on xerographic prints, such an applicationis suitable for low temperature (<100° C.) laminating methods.

Lastly, it is further demonstrated that the bonding between syntheticmedia and laminating films coated with EVA copolymer can be improveddramatically if the amino functional silane is pre-treated by aqueousbuffer solution such as potassium phosphate monobasic aqueous solutionand then incorporated into the adhesives such as EVA copolymer beforethe copolymer is coated on the film (e.g., polyester, polyethylene orpolypropylene films). Because the pre-treatment of silane by using thebuffer solution can dramatically improve the thermal stability ofEVA-based hot melt adhesives and also dramatically improve adhesion ofthe EVA-based hot melt adhesives on xerographic prints, such anapplication is suitable for high temperature (>=100° C.) laminatingmethods.

All the patents and applications referred to herein are herebyspecifically, and totally incorporated herein by reference in theirentirety in the instant specification.

It will be appreciated that various of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. Also thatvarious presently unforeseen or unanticipated alternatives,modifications, variations or improvements therein may be subsequentlymade by those skilled in the art which are also intended to beencompassed by the following claims. Unless specifically recited in aclaim, steps or components of claims should not be implied or importedfrom the specification or any other claims as to any particular order,number, position, size, shape, angle, color, or material.

1. A laminating film for laminating xerographic prints, comprising: aplastic substrate; and an adhesive coating disposed on a surface of theplastic substrate, wherein the adhesive coating comprises an adhesionpromoter comprising a silane coupling component selected from the groupconsisting of a hydrolytic silane compound, a hydrolytic product of ahydrolytic silane compound, and mixtures thereof.
 2. The laminating filmof claim 1, wherein the plastic substrate is selected from the groupconsisting of polyethylene, polypropylene, poly(vinyl chloride),polyester, and mixtures thereof.
 3. The laminating film of claim 1,wherein the adhesive coating is selected from the group consisting of ahot melt adhesive, a pressure sensitive adhesive, and a thermal plasticresin.
 4. The laminating film of claim 1, wherein the adhesive coatingcomprises an ethylene vinyl acetate copolymer resin having vinyl acetatecontent ranging from 15% to 30%.
 5. The laminating film of claim 1,wherein the adhesion promoter is present as a primer at a surface of theadhesive coating.
 6. The laminating film of claim 1, wherein theadhesion promoter is present within the entire adhesive coating at aconcentration ranging from 0.1% to 5% by weight percent of the totaladhesive coating.
 7. The laminating film of claim 1, wherein thehydrolytic silane compound is an amino- or mercapto-functional silanecompound.
 8. The laminating film of claim 1, wherein the silane couplingcomponent comprises the hydrolytic product of a hydrolytic silanecompound mixed with an aqueous buffer solution comprising a buffer agentselected from the group consisting of potassium phosphate dibasic,potassium phosphate monobasic, sodium hydrogen sulfite, and mixturesthereof.
 9. A bonded article, comprising: a xerographic print; anadhesive coating disposed on the xerographic print; a laminating filmdisposed on the adhesive coating, the laminating film comprising aplastic substrate; and an adhesion promoter present at either aninterface between the xerographic print and the adhesive coating orwithin the entire adhesive coating, wherein the adhesion promotercomprises a silane coupling component selected from the group consistingof a hydrolytic silane compound, a hydrolytic product of a hydrolyticsilane compound, and mixtures thereof.
 10. The bonded article of claim9, wherein the xerographic print is printed on a substrate selected fromthe group consisting of a synthetic paper, polyester, polyethylene,polypropylene, poly(vinyl chloride) and mixtures thereof.
 11. The bondedarticle of claim 9, wherein the laminating film is selected from thegroup consisting of polyethylene, polypropylene, poly(vinyl chloride),polyester, and mixtures thereof.
 12. The bonded article of claim 9,wherein the adhesive coating is selected from the group consisting of ahot melt adhesive, a pressure sensitive adhesive, and a thermal plasticresin.
 13. The bonded article of claim 9, wherein the hydrolytic silanecompound contains at least a silane group of —Si(R)3-mXm, wherein R isan non-hydrolyzable organic group, X is a hydrolytic group, and m is aninteger of 1 to
 3. 14. The bonded article of claim 9, wherein thepromoter is hydrolytic silane compound contains in total two of thehydrolytic X group.
 15. The bonded article of claim 9, wherein thehydrolytic silane compound further contains a functional group selectedfrom the group consisting of an amino group, a mercapto group, an epoxygroup, and a vinyl group, and mixtures thereof.
 16. The bonded articleof claim 9, wherein the hydrolytic silane compound is selected from thegroup consisting of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropylethyldiethoxysilane,N-(2-aminoethyl)-3-aminopropyltriethoxysilane4-aminobutyltriethoxysilane, 1-amino-2-(dimethylethoxysilyl)propane,N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane,N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane,(aminoethylaminomethyl)phenethyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropylsilanetriol,N-(6-aminohexyl)aminomethyl-trimethoxysilane,N-(6-aminohexyl)aminopropyl-trimethoxysilane,N-(2-aminoethyl)-11-aminoundecyl-trimethoxysilane,3-aminopropylmethylbis(trimethylsiloxy)silane,3-aminopropyldimethylethoxysilane, 3-aminopropyltrimethoxysilane,3-aminopropyltris(methoxyethoxyethoxy)silane,(3-trimethoxysilylpropyl)diethylene-triamine, and mixtures thereof. 17.The bonded article of claim 9, wherein a silane coupling componentcomprises the hydrolytic product of a hydrolytic silane compound mixedwith an aqueous buffer solution comprising a buffer agent selected fromthe group consisting of potassium phosphate dibasic, potassium phosphatemonobasic, sodium hydrogen sulfite, and mixtures thereof.
 18. The bondedarticle of claim 9, wherein the adhesion promoter is present within theentire adhesive layer at a concentration ranging from 0.1% to 5% byweight percent of the total adhesive.
 19. A method for laminatingxerographic prints, comprising: providing a xerographic print; applyingan adhesive coating on the xerographic print; applying a laminating filmover the xerographic print, wherein the laminating film comprises aplastic substrate, and an adhesive coating disposed on a surface of theplastic substrate, wherein the adhesive coating comprises an adhesionpromoter comprising a hydrolytic silane compound and further wherein thelaminating film is applied in a manner such that the xerographic printcontacts the adhesive coating on a side opposite that which is disposedon the surface of the plastic substrate; and subjecting the xerographicprint and laminating film to heat.
 20. The method of claim 19 furtherincluding subjecting the xerographic print and laminating film topressure.